The present invention relates to a shift lock device and, more specifically, to a shift lock device suitable for a shift-by-wire type shift apparatus that is equipped with a shift lever.
A shift-by-wire type shift device that electrically controls the shifting of shift ranges in a vehicle transmission is known. The conventional shift device detects the operation of the shift lever by a sensor and generates an electrical detection signal. The shift device operates the actuator in accordance with the detection signal to shift the range of the transmission. In shift-by-wire type shift apparatus, a mechanical link structure for transmitting the operation of the shift lever to the transmission is not necessary. Thus, the size of the shift apparatus is easily reduced. Therefore, the shift lever is shifted with a relatively small force and the freedom in laying out the shift apparatus in the passenger compartment is increased.
Some of the shift-by-wire type shift apparatus has no parking range (P) as a shift selection. In such shift apparatus, the ignition switch is turned off while the shift lever is at a reverse (R) range or a forward range.
When parking a vehicle that has the shift apparatus, the shift lever is operated to an appropriate shift range in accordance with the condition of the vehicle, such as when parking the vehicle on a slope. For example, when parking the vehicle on an ascending slope, the shift lever is operated to the forward range to prevent the vehicle from moving backward and descending the slope. Also, for example, when parking the vehicle on a descending slope, the shift lever is operated to the reverse range (R) to prevent the vehicle from advancing and descending the slope.
As described above, the shift lever is operated to the appropriate shift range in accordance with the condition of the vehicle and locked at the selected shift range to park the vehicle.
A lock device may include solenoids in association with the shift ranges of the shift lever. A plunger of each solenoid may be formed to project to block a shift gate thereby locking the shift lever.
However, providing a solenoid to each of the shift ranges increases the number of the solenoids, causing eventually the increase of the manufacturing cost. Furthermore, a growth of the number of the solenoids results in a large space for arranging the solenoids. This hinders the size reduction of the shift apparatus.